Sunday, March 18, 2018

Modular Volumetrics - More Than Just Empty Space

For the past few months I’ve been hearing the benefits of panelized walls, trusses and prefab floor systems built off site and shipped to the job site where they can be assembled in one or two days ready for the subcontractors to take over.


Companies like Entekra have some of the most powerful and effective marketing pounding away at anyone that simply Googles ‘new home construction’. Their ads will find you no matter what site you visit including this one.

One of the biggest arguments made for panelized or ‘stackable’ walls is they can be placed on a standard flatbed trailer and sent hundreds of miles without extra tariffs and escort vehicles. This makes a lot of sense to contractors both small and large.


Modular construction on the other hand almost always requires special permits (added costs) and escort vehicles (added costs) and the specialized trailers used to transport modular homes must be stacked on the jobsite for the trip back home which is a deadhead trip costing, you guessed it, more money.

And many tract builders, the folks that should really be embracing modular home construction, always play the “Delivering Empty Space” card as a their excuse for not using modular.

Now let’s take a look at the ‘empty space’ trump card. Yes there is a lot of open area in a modular being shipped hundreds of miles. And yes, modular home builders pay a dear price to get those modules delivered to the jobsite but is there gold in that empty space!
Before the modular home leaves the factory gate on its specialized carrier on its long trip to its new home site and new family waiting for it to be delivered, a lot of really wonderful things has been built into that ‘empty space’.

A module isn’t simply an empty box stuck on a trailer. A lot of really good things are inside. Assuming the panel people are using the same 2x6s, 2x8, LVLs and framing hangers used in modular production, you can see that both methods, panelized and modular, use the best lumber available.

Day one at a panelized house set sees the floor and walls of the 2 story home go up. Day two is usually the trusses, roof sheathing and the attached garage. Day three the house is turned over to the builder. Windows go in and the electricians or maybe the plumbers show up. If they are actually available to move in when the house is ready. Always a crap shoot unless you’re a tract builder who demands they be there or face penalties.

With so much work available to these trades, do they really need that kind of pressure when they can make more money and overbook their workload and still find builders eager to have them on their jobs.

After the these two trades leave the house, usually within a week or two, the wall insulation people move in followed by the drywall subs. Drywall subs are always on time and finish on time and never hold up the job....Well, not in my experience as a General Contractor, where I found that I had to give these Prima Donna’s as much time as they want or you won’t get them back to finish the drywall for weeks.

Then the next group of high skilled people show up. The trim-out people. Always in demand and overbooked, they usually take their own sweet time getting to the job and getting them to stay on the job continuously until its completed is a rarity.

Kitchen cabinet installation always seems to drag out as does the HVAC people, the roofers, siding crews, carpet/wood floor installers, tile workers and painters.

That two day job of having the panelized house shell finished has turned into at least 90-180 days before the house is ready to hand over to the customer. Oh, did I mention the myriad of local code inspections required at the framing, rough-in and the numerous re-inspections, where the local government makes as much money per house as setting up a speed trap into the town?

This brings us to the ‘empty space’ in the modules being shipped down the road. About 80% of the above mentioned things a new home that has to be completed on site is actually done on the modular home production line. The modules are shipped to the homeowners foundation where in one or two days that empty space is set by a crane and a set crew and ready to hand over to the builder for final finish work.

That empty space wasn’t so empty after all. No pesky local code inspectors can re-inspect any of the work done in the factory as the third party inspection services have already signed off on those parts of the home that would normally hold up a site built home for up to a week for each inspection and/or re-inspection.

Once the modular house is ‘weather-tight’ which happens in one or two days, the builder simply has his crew begin working on such things as the marriage wall finishing, porches and miscellaneous drywall work. Exterior siding is completed, final plumbing and electrical connections are made and all the special order items that may have to be installed after delivery of the home is completed.

All this can be done on a standard home in about 30 days while a more complicated one with special exterior and site installed tile work might take up to 90. Either way the modular home goes up quicker which means the homeowner is making fewer interest only construction loan payments and can move into their new home.


The next time a tract builder or a panelized wall or truss factory says that modular homes are just full of empty space when they are on the road, tell them “No!” it’s packed with hundreds of hours of skilled labor work, a lot of inspections that don’t need made and finally it’s just jam packed with money that the new homeowner has saved by using modular.

2 comments:

Chris said...

Interesting article, personally i think there might be quite a variance globally in weather this works out aws a great idea or an expensive one, plus also what modular material are you using?
we have customers building modular homes and spaces from shipping containers. these require no permits, delivery mileages are usually pretty short as there will be a container yard nearby where we can source from, hand one way haulage can often be covered on a backload basis by finding a local haulier who will deliver for a lot less, if tis done on the basis of 'as and when they have an truck passing the yard heading home empty', these measures can help keep costs down considerably but then the material does mean there is still a fair bit of work to do once delivered to make them into a home.

Tom Hardiman said...

No permits needed to build a home from a shipping container? I'm betting a permit is needed, and someone just getting it. And I don't know of too many that are buying an ISO container straight from the container yard and delivering to the site, then modifying on site. I think the container architecture concept will grow but I promise you it will be more closely regulated now that its on every one's radar screen.

Several states are addressing this and it is currently being proposed for the 2021 IBC.